Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Sensors (Basel) ; 22(5)2022 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-35270894

RESUMEN

The authors of this study developed the use of attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) combined with machine learning as a point-of-care (POC) diagnostic platform, considering neonatal respiratory distress syndrome (nRDS), for which no POC currently exists, as an example. nRDS can be diagnosed by a ratio of less than 2.2 of two nRDS biomarkers, lecithin and sphingomyelin (L/S ratio), and in this study, ATR-FTIR spectra were recorded from L/S ratios of between 1.0 and 3.4, which were generated using purified reagents. The calibration of principal component (PCR) and partial least squares (PLSR) regression models was performed using 155 raw baselined and second derivative spectra prior to predicting the concentration of a further 104 spectra. A three-factor PLSR model of second derivative spectra best predicted L/S ratios across the full range (R2: 0.967; MSE: 0.014). The L/S ratios from 1.0 to 3.4 were predicted with a prediction interval of +0.29, -0.37 when using a second derivative spectra PLSR model and had a mean prediction interval of +0.26, -0.34 around the L/S 2.2 region. These results support the validity of combining ATR-FTIR with machine learning to develop a point-of-care device for detecting and quantifying any biomarker with an interpretable mid-infrared spectrum.


Asunto(s)
Aprendizaje Automático , Síndrome de Dificultad Respiratoria del Recién Nacido , Biomarcadores , Humanos , Recién Nacido , Análisis de los Mínimos Cuadrados , Espectroscopía Infrarroja por Transformada de Fourier/métodos
2.
Opt Lett ; 43(12): 2913-2916, 2018 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-29905722

RESUMEN

We demonstrate the integration of paper fluidics with mid-infrared (MIR) chalcogenide waveguides to introduce liquid samples to the waveguide evanescent field for analysis. Spectroscopy of model analytes (water and isopropyl alcohol) having well-defined mid-IR absorptions, on a ZnSe rib waveguide fabricated on silicon, is demonstrated in the wavelength range of 2.6-3.7 µm, showing their O-H and C-H stretching absorptions. The results are compared with a theoretical waveguide model, achieving good agreement. It is concluded that the presence of paper in the evanescent field does not interfere with the waveguide measurements, opening up opportunities to combine low-cost paper-based fluidics and integrated photonic technologies.

3.
J Craniofac Surg ; 28(3): 693-695, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28468150

RESUMEN

BACKGROUND: Craniofacial teams employ multidisciplinary clinics to optimize patient care. Different clinic formats exist among teams. Formats include providers rotating from room to room as separate specialties, patients rotating from room to room to either separate specialties or as 1 group, as well as providers rotating together as 1 group. Surveys were used to study family preferences between the different formats and to compare them with trends of national practices. METHODS: Families of the authors' team clinic patients were surveyed from November 2012 to February 2013, after a clinic format change from patients moving between rooms to see providers, to providers moving between rooms to see patients. This survey focused on patient satisfaction, clinic format preference, and their perception of efficiency. A second, national survey was distributed to 161 American craniofacial teams approved by the American Cleft Palate-Craniofacial Association to survey clinic formats, provider satisfaction, and experience with other formats. Institutional survey data were tabulated as percentages and further analyzed using the Mann-Whitney Test. The national survey data was then tabulated and compared with authors' institutional results. RESULTS: Thirty-nine of 54 (72.2%) families responded to the institutional survey. Providers moving between rooms were associated with greater patient satisfaction (mean 4.8 of 5, 5 being most satisfied) (0<0.0001), shorter perceived clinic time (76.9%), and an increased sense of comfort (84.6%). The difference in satisfaction rates was statistically significant (P <0.0001) between the primary clinic formats of providers rotating (mean of 4.8) and patients rotating (mean of 2.4).The national survey had 93 responses of 161 (57.7%). 54.9% of respondents have providers rotating between examination rooms, and 32.3% have patients moving between rooms. Other formats included the entire team moving as a group between rooms (10.8%) and specialties sitting together in 1 room while patients rotate (9.7%). Respondents were satisfied with current formats (mean 4.24 of 5, 5 being most satisfied). 22.2% had tried a different format previously. CONCLUSION: The most common American cleft and craniofacial clinic format is providers moving between rooms; however, all formats have high provider satisfaction. At our institution, patients prefer when providers move between rooms. Our study suggests that clinic formats do not need to be standardized, and the clinic format utilized should be tailored to the individual needs of the institution.


Asunto(s)
Fisura del Paladar/cirugía , Procedimientos Quirúrgicos Orales/normas , Satisfacción del Paciente , Procedimientos de Cirugía Plástica/normas , Sociedades Médicas , Adolescente , Niño , Preescolar , Femenino , Humanos , Masculino , Encuestas y Cuestionarios , Estados Unidos
4.
Nanotechnology ; 27(32): 325703, 2016 Aug 12.
Artículo en Inglés | MEDLINE | ID: mdl-27348305

RESUMEN

The light emission properties of silicon crystalline nanoparticles (SiNPs) have been investigated using steady-state and time-resolved photoluminescence measurements carried out at 12 K and at room temperature. To enable a comparative study of the role of surface terminal groups on the optical properties, we investigated SiNPs-H ensembles with the same mean NP diameter but differing on the surface termination, namely organic-functionalized with 1-dodecene (SiNPs-C12) and H-terminated (SiNPs-H). We show that although the spectral dependence of the light emission is rather unaffected by surface termination, characterized by a single broad band peaking at ∼1.64 eV, both the exciton recombination lifetimes and quantum yields display a pronounced dependence on the surface termination. Exciton lifetimes and quantum yields are found to be significantly lower in SiNPs-H compared SiNPs-C12. This difference is due to distinct non-radiative recombination probabilities resulting from inter-NP exciton migration, which in SiNPs-C12 is inhibited by the energy barriers imposed by the bulky surface groups. The surface groups of organic-terminated SiPs are responsible for the inhibition of inter-NP exciton transfer, yielding a higher quantum yield compared to SiNPs-H. The surface oxidation of SiNPs-C12 leads to the appearance of a phenomenon of an exciton transference from to the Si core to oxide-related states that contribute to light emission. These excitons recombine radiatively, explaining why the emission quantum of the organic-terminated SiNPs is the same after surface oxidation of SiNPs-C12.

5.
Aesthet Surg J ; 35(6): NP169-75, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25969435

RESUMEN

BACKGROUND: Three-dimensional (3D) changes in the midface following malar calcium hydroxyapatite (CaHa) injection have not been systematically analyzed. OBJECTIVES: The authors analyzed 3D volume changes in midface and naso-labial fold (NLF) volume, as well as lateral movement in the NLF/naso-labial crease (NLC) junction following malar injection of CaHa in a cadaver model. METHODS: A single surgeon injected CaHa in the supraperiosteal plane. Sequential images were obtained with the VECTRA 3D system pre- and post-1.5- and 3-cc CaHa injections. All measurements were performed by a single examiner. Injection location was verified anatomically. RESULTS: Injections were performed in 16 fresh cadaver hemi-faces. Maximal increases in projection were centered on the malar injection site, with associated decreases in projection and volume in the infero-medial locations. Relative mean increases in volume of 3.16 cc and 4.94 cc were observed following the 1.5-cc and 3-cc injections, respectively. There was a relative decrease in the volume of the NLF of -0.3 cc and -0.4 cc following the 1.5- and 3-cc injections, respectively. Injection of CaHa was associated with lateral movements of the NLF-NLC junction at the level of the nasal sill, philtral columns, and oral commissure, measuring 2.7, 2.5, and 1.9 mm and 2.8, 2.9, and 2.4 mm following the 1.5- and 3-cc injections, respectively. Anatomical dissection verified the location in the supraperiosteal space and within the middle malar fat pad. CONCLUSIONS: Following malar CaHa injection, 3D photographic analysis showed a measureable lifting effect with recruitment of ptotic tissue and lateral movement of the NLF-NLC junction in a cadaver model.


Asunto(s)
Técnicas Cosméticas , Rellenos Dérmicos/administración & dosificación , Durapatita/administración & dosificación , Cara/anatomía & histología , Rejuvenecimiento , Envejecimiento de la Piel , Anciano , Anciano de 80 o más Años , Cadáver , Estética , Femenino , Humanos , Imagenología Tridimensional , Inyecciones Intradérmicas , Masculino , Fotograbar
6.
Nano Lett ; 13(3): 1317-22, 2013 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-23413833

RESUMEN

Localized surface plasmon resonances (LSPRs) enable tailoring of the optical response of nanomaterials through their free carrier concentration, morphology, and dielectric environment. Recent efforts to expand the spectral range of usable LSPR frequencies into the infrared successfully demonstrated LSPRs in doped semiconductor nanocrystals. Despite silicon's importance for electronic and photonic applications, no LSPRs have been reported for doped silicon nanocrystals. Here we demonstrate doped silicon nanocrystals synthesized via a nonthermal plasma technique that exhibits tunable LSPRs in the energy range of 0.07-0.3 eV or mid-infrared wavenumbers of 600-2500 cm(-1).

7.
Plast Reconstr Surg Glob Open ; 9(7): e3678, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-34262839

RESUMEN

Injectable drug use in the upper extremity often leads to chronic wounds complicated by osteomyelitis. Conventional reconstructive options are often not feasible and/or are contraindicated in this patient population. We have started using a synthetic, biodegradable temporizing matrix (BTM) for the treatment of these patients. We hypothesize that BTM is a safe, low-risk, and low-morbidity alternative reconstructive option. We report outcomes after staged debridement and BTM application followed by split-thickness skin grafting for two patients with large, chronic bilateral forearm wounds with concomitant osteomyelitis confirmed by MRI and biopsy. No acute surgical complications were encountered and at a mean follow-up of 13 months, both patients had maintained stable soft-tissue coverage. Reconstruction using BTM is a novel treatment option that can simplify the reconstruction, reduce donor-site morbidity, and optimize success for patients with chronic wounds resulting from injectable drug use. Initial outcomes are promising; however, further comparative studies are needed to better evaluate long-term outcomes of this technique.

8.
Biosensors (Basel) ; 11(11)2021 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-34821633

RESUMEN

Recent advances suggest that miniaturised mid-infrared (MIR) devices could replace more time-consuming, laboratory-based techniques for clinical diagnostics. This work uses Fourier transform infrared spectroscopy to show that the MIR complex refractive index of whole blood varies across a range of haematocrit. This indicates that the use of an evanescent measurement is not sufficient to optically exclude the cellular content of blood in the MIR, as previously assumed. Here, spectral refractive index data is presented in two ways. First, it is given as whole blood with varying haematocrit. Second, it is given as the percentage error that haematocrit introduces to plasma. The maximum error in the effective plasma refractive index due to the haematocrit of healthy adults was 0.25% for the real part n and 11% for the imaginary part k. This implies that calibration measurements of haematocrit can be used to account for errors introduced by the cellular content, enabling plasma spectra and analyte concentrations to be indirectly calculated from a whole blood sample. This methodological advance is of clinical importance as plasma concentration of analytes such as drugs can be determined using MIR without the preprocessing of whole blood.


Asunto(s)
Hematócrito , Refractometría , Espectroscopía Infrarroja por Transformada de Fourier , Humanos , Preparaciones Farmacéuticas , Plasma
9.
Aesthet Surg J ; 29(2): 150-7, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19371848

RESUMEN

Most medications, herbal preparations, and nutraceutical supplements have notable effects on biochemical pathways and may influence wound healing, coagulation, and cardiovascular function. They can also interact with other drugs. A large portion of the data available regarding the effects of naturopathic medicines is anecdotal. Marketing of certain products may be misleading and potentially harmful, and quality control standards are highly variable. In order to ensure quality control and standardization of products, it is prudent to work with preparations manufactured by companies that adhere to pharmaceutical (good manufacturing practice [GMP]) standards. However, many of these higher-quality products are not readily available to the public over the counter. A large percentage of patients undergoing plastic surgery use one or more herbal medications, but the disclosure of such medications to allopathic providers is often incomplete. In addition, patients may not understand the importance of discontinuing such medications before surgery. The authors review research on the possible benefits and risks of commonly used herbal medications such as arnica montana, St. John's wort, bromelain, echinacea, ginkgo biloba, ephedra, valerian, and others, focusing on their potentially positive or negative impact during the perioperative period of aesthetic surgery. Good communication with surgical patients, including the administration of a presurgical questionnaire to help identify any use of herbal medications, is emphasized.


Asunto(s)
Suplementos Dietéticos/efectos adversos , Atención Perioperativa , Preparaciones de Plantas/efectos adversos , Procedimientos de Cirugía Plástica , Arnica/efectos adversos , Arnica/metabolismo , Bromelaínas/efectos adversos , Bromelaínas/metabolismo , Interacciones Farmacológicas , Echinacea/efectos adversos , Echinacea/metabolismo , Ephedra/efectos adversos , Ephedra/metabolismo , Ginkgo biloba/efectos adversos , Ginkgo biloba/metabolismo , Interacciones de Hierba-Droga , Humanos , Hypericum/efectos adversos , Hypericum/metabolismo , Preparaciones de Plantas/metabolismo , Control de Calidad , Cirugía Plástica , Valeriana/efectos adversos , Valeriana/metabolismo
10.
Tech Hand Up Extrem Surg ; 23(3): 143-145, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31454335

RESUMEN

Wrist arthrodesis in the setting of segmental bone loss can have high failure rates. Therefore, vascularized bone grafting has been advocated for select patients. Patients suffering concomitant large soft tissue loss present even greater challenge. To that end, we describe for the first time successful anterolateral thigh-medial femoral condyle chimeric flow-through flap for posttraumatic wrist arthrodesis and soft tissue coverage. This is a case report of a 19-year-old male laborer who suffered a large blast injury resulting in significant bone and soft tissue injury to the dominant right hand and wrist. After multiple debridements, there was a segmental bone defect from the distal radius and ulna to the metacarpal bases, as well as a 12×8 cm dorsal soft tissue defect. This was reconstructed with a anterolateral thigh-medial femoral condyle chimeric flow-through flap and concomitant wrist arthrodesis in a single stage. Besides a donor site thigh seroma, recovery was uneventful with clinical and radiographic evidence of fusion by >9 weeks postoperation.


Asunto(s)
Artrodesis , Fémur/trasplante , Colgajos Quirúrgicos , Articulación de la Muñeca/cirugía , Traumatismos por Explosión/cirugía , Humanos , Masculino , Traumatismos de los Tejidos Blandos/cirugía , Colgajos Quirúrgicos/irrigación sanguínea , Traumatismos de la Muñeca/cirugía , Adulto Joven
11.
Aesthet Surg J ; 28(1): 46-50, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19083505

RESUMEN

BACKGROUND: Aesthetic analysis of the face is best accomplished by dividing the face into equal thirds. A long forehead may lend the appearance of a less attractive, disproportionate, and senescent face. OBJECTIVE: To provide data regarding options for surgical correction of the long forehead. METHODS: Patients complaining of excess forehead length were divided into 3 groups on the basis of forehead length in relation to other facial proportions. Patients with mild elongation underwent an endoscopic forehead lift, those with moderate elongation underwent an open forehead lift, and those with severe forehead elongation underwent open forehead shortening. RESULTS: A total of 755 patients were evaluated, including 702 women and 53 men undergoing forehead surgery since 1998. Follow-up ranged from 12 months to 8 years. Four hundred thirty-eight patients underwent endoscopic forehead lift for mild forehead elongation, 297 patients underwent pretrichial forehead lift for moderate elongation, and 20 patients underwent major scalp advancement for severe forehead elongation. Successful forehead rejuvenation was achieved in all groups. Complications were minor and included alopecia and delayed wound healing. CONCLUSIONS: An optimally proportioned forehead may be achieved by use of a variety of elective operations on the basis of severity of forehead excess and geared to reducing forehead length.


Asunto(s)
Frente/cirugía , Rejuvenecimiento , Ritidoplastia/métodos , Alopecia/etiología , Alopecia/cirugía , Belleza , Cefalometría/métodos , Músculos Faciales/cirugía , Femenino , Estudios de Seguimiento , Frente/anatomía & histología , Humanos , Masculino , Examen Físico , Estudios Retrospectivos , Cuero Cabelludo/cirugía , Resultado del Tratamiento
13.
Sci Rep ; 7(1): 7356, 2017 08 04.
Artículo en Inglés | MEDLINE | ID: mdl-28779085

RESUMEN

Mid-infrared (MIR) spectroscopy is a powerful tool for characterising the vibrations of molecular bonds and is therefore ideal for label-free detection of chemical species. Recent research into thin-film deposition and etching techniques for mid-infrared materials shows potential for realising miniaturised bedside biosensors for clinical diagnostics exploiting MIR spectroscopy, to replace laboratory based-techniques. However, lack of refractive index information for commonly encountered biological media and analytes hampers optimisation of biosensor performance for maximum sensitivity, especially for devices exploiting evanescent spectroscopy. Here we present refractive index data for human whole blood and several aqueous solutions of general interest to the clinical community: anticoagulants, analgesics and buffers. The refractive indices are generally dominated by the water content of each sample and the whole blood spectra exhibit additional strong features due to protein content. Furthermore, we present a generalised method for extracting complex refractive indices of aqueous solutions in the mid-infrared region using conventional attenuated total reflection Fourier transform spectroscopy (ATR-FTIR) without the need for collimated or polarised incident light, as is required for existing methods.


Asunto(s)
Analgésicos/sangre , Analgésicos/química , Anticoagulantes/sangre , Anticoagulantes/química , Tampones (Química) , Espectrofotometría Infrarroja , Humanos , Soluciones , Espectroscopía Infrarroja por Transformada de Fourier
14.
Chem Commun (Camb) ; (18): 2284-5, 2003 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-14518876

RESUMEN

The in situ oxidation-Wittig reaction, followed by subsequent hydrolysis, has been applied to the conversion of primary alcohols into alpha,beta-unsaturated aldehydes. This conversion, which proceeds via the intermediacy of the homologated unsaturated dioxolanes, gives good to excellent yields with a range of benzylic alcohols and heterocyclic methanols.

15.
Hand (N Y) ; 6(1): 64-70, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22379441

RESUMEN

Hand-arm vibration syndrome (HAVS) is a debilitating sequela of neurological and vascular injuries caused by prolonged occupational exposure to hand-transmitted vibration. Our previous study demonstrated that short-term exposure to vibration can induce vasoconstriction and endothelial cell damage in the ventral artery of the rat's tail. The present study investigated whether pretreatment with D-4F, an apolipoprotein A-1 mimetic with known anti-oxidant and vasodilatory properties, prevents vibration-induced vasoconstriction, endothelial cell injury, and protein nitration. Rats were injected intraperitoneally with 3 mg/kg D-4F at 1 h before vibration of the tails for 4 h/day at 60 Hz, 49 m/s(2) r.m.s. acceleration for either 1 or 3 days. Vibration-induced endothelial cell damage was examined by light microscopy and nitrotyrosine immunoreactivity (a marker for free radical production). One and 3-day vibration produced vasoconstriction and increased nitrotyrosine. Preemptive treatment with D-4F prevented these negative changes. These findings suggest that D-4F may be useful in the prevention of HAVS.

17.
Plast Reconstr Surg ; 123(4): 1321-1331, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19337100

RESUMEN

BACKGROUND: The purpose of this study was to identify the environmental factors that contribute to facial aging in identical twins. METHODS: During the Twins Day Festival in Twinsburg, Ohio, 186 pairs of identical twins completed a comprehensive questionnaire, and digital images were obtained. A panel reviewed the images independently and recorded the differences in the perceived twins' ages and their facial features. The perceived age differences were then correlated with multiple factors. RESULTS: Four-point higher body mass index was associated with an older appearance in twins younger than age 40 but resulted in a younger appearance after age 40 (p = 0.0001). Eight-point higher body mass index was associated with an older appearance in twins younger than age 55 but was associated with a younger appearance after age 55 (p = 0.0001). The longer the twins smoked, the older they appeared (p < 0.0001). Increased sun exposure was associated with an older appearance and accelerated with age (p = 0.015), as was a history of outdoor activities and lack of sunscreen use. Twins who used hormone replacement had a younger appearance (p = 0.002). Facial rhytids were more evident in twins with a history of skin cancer (p = 0.05) and in those who smoked (p = 0.005). Dark and patchy skin discoloration was less prevalent in twins with a higher body mass index (p = 0.01) and more common in twins with a history of smoking (p = 0.005) and those with sun exposure (p = 0.005). Hair quantity was better with a higher body mass index (p = 0.01) although worse with a history of skin cancer (p = 0.005) and better with the use of hormones (p = 0.05). CONCLUSION: This study offers strong statistical evidence to support the role of some of the known factors that govern facial aging.


Asunto(s)
Cara/anatomía & histología , Envejecimiento de la Piel , Gemelos Monocigóticos , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
18.
Clin Plast Surg ; 35(3): 355-60; discussion 353, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18558228

RESUMEN

Endoscopic forehead rejuvenation has several advantages over traditional open techniques. First, large incisional scars are avoided. Second, the chances of forehead elongation are less. However, the technique requires a significant learning curve for best results. Suboptimal results may occur and are typically due to underresection or uneven resection of the glabellar musculature, overdissection of the medial periosteum, and under or overcorrection when repositioning of the lateral brow. This article reviews the pertinent anatomy and techniques for endoscopic forehead rejuvenation, and describes the authors' technique for more consistent, predictable results.


Asunto(s)
Endoscopía/métodos , Frente/cirugía , Ritidoplastia/métodos , Cejas/anatomía & histología , Músculos Faciales/anatomía & histología , Músculos Faciales/cirugía , Frente/anatomía & histología , Humanos , Examen Físico
19.
J Reconstr Microsurg ; 23(5): 237-42, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17876725

RESUMEN

Despite recent advances in microsurgery, the incidence of thrombosis of repaired digital vessels following crush injury is higher than that of uncrushed arteries. The purpose of this study was to evaluate the effects of traumatic crush injury on uncrushed segments of artery adjacent to crushed segments. Sprague-Dawley rat-tail arteries were crushed for 1 hour by 30 pounds of force at two separate 3-mm-wide segments, with 10 mm of uncrushed artery between segments. Luminal size of the uncrushed segments decreased progressively over the first 12 hours, with a significant reduction by 4 hours postcrush. The condition of the arteries continued to deteriorate until, by 24 hours postinjury, they had been denuded of endothelium, and smooth muscle damage had occurred. Untreated vasospasm following a multiple-level crush injury therefore results in progressive endothelial and intimal damage and thrombosis in the intervening healthy uncrushed segments of artery. This article discusses the implications of these findings.


Asunto(s)
Síndrome de Aplastamiento/fisiopatología , Enfermedades Vasculares Periféricas/fisiopatología , Animales , Síndrome de Aplastamiento/complicaciones , Síndrome de Aplastamiento/patología , Endotelio Vascular/patología , Endotelio Vascular/fisiopatología , Masculino , Músculo Liso Vascular/patología , Enfermedades Vasculares Periféricas/etiología , Enfermedades Vasculares Periféricas/patología , Ratas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA